Wednesday, February 15, 2012

Why do bioluminescent bays glow?

Bioluminescence in the bioluminescent bays is caused by microscopic single-celled creatures called dinoflagellates. The conditions in these bays are such that allow an abundance of these organisms to thrive. There are about 750,000 tiny dinoflagellates per gallon of water that light up when they are touched.

The bilomuniscent dinoflagellates Pyrodinium bahamense are a photosynthesis-using plankton. They are one celled and measure about 1/500th of an inch. A tiny burst of light it gives off is a hundred times bigger than itself. Each dinoflagellate bursts into light when it feels pressure against its cell wall. The light is given off in an instantaneous process; when you add the light bursts of 750,000 dinoflagellates per cubic foot of water together, the effect is spectacular.

Dinoflagellates are organisms that are part of the Protista kingdom. Most dinoflagellates are algae, so they can produce their own food through photosynthesis. They possess tiny flagellates (Latin for whip), which are tail-like appendages that propel them through the water. Photosynthesis in dinoflagellates involves light being captures by their chlorophyll, which has bluish-green pigment (as opposed to plants which have green chlorophyll). What sets this cholorophyll apart is that it becomes luminescent when agitated.

The bioluminescent bay in Fajardo has three key attributes for attracting dinoflagellates. First it shallow waters and a narrow exit to the sea, allowing for the organisms to concentrate in its shallow refuge. Two, because the bay is small in size, water does not rush out of it quickly. Three, it has a high concentration of mangroves. Mangroves are important to dinoflagellates because they are a good source of vitamin B12, which is essential for dinoflagellates to survive. Mangroves release a large amount of vitamin B12 and so dinoflagellates conglomerate in the bay.